Nucleic Acids, DNA Structure, and Chromosomes Nucleotides are the building blocks of nucleic acids One (NMP), two (NDP), three (NTP) phosphates 5 different bases: A, G, C (DNA and RNA), T (DNA), U (RNA) 2 different sugars: ribose (RNA), deoxyribose (DNA) Two kinds of 5-carbon sugars Five kinds of nitrogen containing bases The sugars and bases are linked through a glycosidic bond nucleoside = N-containing base linked to a 5 carbon sugar (no phosphate) nucleotide = N-containing base linked to a 5 carbon sugar & one or more phosphates Nucleotides are linked through phosphodiester bonds Link between nucleotides: 5? C of sugar - phosphate- 3? C of sugar (backbone) Variable portion: base